using UnityEngine;
using UnityEngine.UI;

/// <summary>
/// Шкала здоровья Босса вверху посередине экрана.
/// Показывает имя босса, текущее/максимальное здоровье и плавное заполнение полосы.
/// </summary>
public class BossHealthBarUI : MonoBehaviour
{
    private static BossHealthBarUI _instance;
    public static BossHealthBarUI Instance
    {
        get
        {
            if (_instance == null)
                _instance = FindAnyObjectByType<BossHealthBarUI>(FindObjectsInactive.Include);
            return _instance;
        }
    }

    [Header("Элементы интерфейса")]
    public GameObject rootPanel;
    public Text bossTitleText;
    public Text bossSubText;
    public Image fillBar;
    public Text healthValueText;
    public CanvasGroup canvasGroup;

    private float targetFill = 1f;
    private float currentFill = 1f;
    private bool isVisible = false;

    public static BossHealthBarUI Create(Transform hudCanvas)
    {
        var old = hudCanvas.Find("BossHealthBarPanel");
        if (old != null) DestroyImmediate(old.gameObject);

        Font defaultFont = Resources.GetBuiltinResource<Font>("LegacyRuntime.ttf");

        // 1. Корневой объект
        GameObject root = new GameObject("BossHealthBarPanel", typeof(RectTransform), typeof(CanvasGroup));
        root.transform.SetParent(hudCanvas, false);

        RectTransform rootRt = root.GetComponent<RectTransform>();
        rootRt.anchorMin = new Vector2(0.5f, 1.0f);
        rootRt.anchorMax = new Vector2(0.5f, 1.0f);
        rootRt.pivot = new Vector2(0.5f, 1.0f);
        rootRt.anchoredPosition = new Vector2(0f, -22f);
        rootRt.sizeDelta = new Vector2(560f, 62f);

        // 2. Фон контейнера
        Image bgImg = root.AddComponent<Image>();
        bgImg.color = new Color(0.04f, 0.04f, 0.05f, 0.92f);

        Outline outline = root.AddComponent<Outline>();
        outline.effectColor = new Color(1.0f, 0.25f, 0.25f, 0.65f);
        outline.effectDistance = new Vector2(1.5f, -1.5f);

        // 3. Заголовок босса
        GameObject titleObj = new GameObject("BossTitle", typeof(RectTransform), typeof(CanvasRenderer), typeof(Text));
        titleObj.transform.SetParent(root.transform, false);
        RectTransform titleRt = titleObj.GetComponent<RectTransform>();
        titleRt.anchorMin = new Vector2(0f, 0.62f);
        titleRt.anchorMax = new Vector2(1f, 1.0f);
        titleRt.offsetMin = new Vector2(15f, 0f);
        titleRt.offsetMax = new Vector2(-15f, -4f);

        Text titleText = titleObj.GetComponent<Text>();
        titleText.font = defaultFont;
        titleText.fontSize = 15;
        titleText.fontStyle = FontStyle.Bold;
        titleText.alignment = TextAnchor.MiddleCenter;
        titleText.color = new Color(1.0f, 0.3f, 0.3f, 1.0f);
        titleText.text = "ТИП-0: АЛЬФА-МУТАНТ (ПАТРИАРХ)";

        // 4. Фон полосы здоровья
        GameObject barBgObj = new GameObject("BarBackground", typeof(RectTransform), typeof(CanvasRenderer), typeof(Image));
        barBgObj.transform.SetParent(root.transform, false);
        RectTransform barBgRt = barBgObj.GetComponent<RectTransform>();
        barBgRt.anchorMin = new Vector2(0f, 0.16f);
        barBgRt.anchorMax = new Vector2(1f, 0.54f);
        barBgRt.offsetMin = new Vector2(14f, 0f);
        barBgRt.offsetMax = new Vector2(-14f, 0f);

        Image barBgImg = barBgObj.GetComponent<Image>();
        barBgImg.color = new Color(0.18f, 0.05f, 0.05f, 0.95f);

        // 5. Заполнение полосы (красный градиент)
        GameObject fillObj = new GameObject("BarFill", typeof(RectTransform), typeof(CanvasRenderer), typeof(Image));
        fillObj.transform.SetParent(barBgObj.transform, false);
        RectTransform fillRt = fillObj.GetComponent<RectTransform>();
        fillRt.anchorMin = Vector2.zero;
        fillRt.anchorMax = Vector2.one;
        fillRt.sizeDelta = Vector2.zero;

        Image fillImg = fillObj.GetComponent<Image>();
        fillImg.type = Image.Type.Filled;
        fillImg.fillMethod = Image.FillMethod.Horizontal;
        fillImg.fillOrigin = (int)Image.OriginHorizontal.Left;
        fillImg.color = new Color(0.95f, 0.2f, 0.2f, 1.0f);

        // 6. Текст числового значения HP
        GameObject hpTxtObj = new GameObject("HealthText", typeof(RectTransform), typeof(CanvasRenderer), typeof(Text));
        hpTxtObj.transform.SetParent(barBgObj.transform, false);
        RectTransform hpTxtRt = hpTxtObj.GetComponent<RectTransform>();
        hpTxtRt.anchorMin = Vector2.zero;
        hpTxtRt.anchorMax = Vector2.one;
        hpTxtRt.sizeDelta = Vector2.zero;

        Text hpTxt = hpTxtObj.GetComponent<Text>();
        hpTxt.font = defaultFont;
        hpTxt.fontSize = 13;
        hpTxt.fontStyle = FontStyle.Bold;
        hpTxt.alignment = TextAnchor.MiddleCenter;
        hpTxt.color = Color.white;
        hpTxt.text = "500 / 500";

        BossHealthBarUI barUI = root.AddComponent<BossHealthBarUI>();
        barUI.rootPanel = root;
        barUI.bossTitleText = titleText;
        barUI.fillBar = fillImg;
        barUI.healthValueText = hpTxt;
        barUI.canvasGroup = root.GetComponent<CanvasGroup>();
        barUI.canvasGroup.alpha = 0f;
        barUI.canvasGroup.blocksRaycasts = false;
        barUI.canvasGroup.interactable = false;

        root.SetActive(false);
        return barUI;
    }

    private void Awake()
    {
        _instance = this;
        if (canvasGroup == null) canvasGroup = GetComponent<CanvasGroup>();
    }

    private void Update()
    {
        // Плавное заполнение полосы
        currentFill = Mathf.MoveTowards(currentFill, targetFill, 2.5f * Time.deltaTime);
        if (fillBar != null)
        {
            fillBar.fillAmount = currentFill;
        }

        // Плавный альфа-фейд
        if (canvasGroup != null)
        {
            float targetAlpha = isVisible ? 1f : 0f;
            canvasGroup.alpha = Mathf.MoveTowards(canvasGroup.alpha, targetAlpha, 4f * Time.deltaTime);

            if (!isVisible && canvasGroup.alpha <= 0.01f && gameObject.activeSelf)
            {
                gameObject.SetActive(false);
            }
        }
    }

    public void ShowBoss(string name, float current, float max)
    {
        if (bossTitleText != null) bossTitleText.text = name;
        targetFill = Mathf.Clamp01(current / max);
        currentFill = targetFill;
        if (fillBar != null) fillBar.fillAmount = currentFill;
        if (healthValueText != null) healthValueText.text = $"{Mathf.CeilToInt(current)} / {Mathf.CeilToInt(max)}";

        gameObject.SetActive(true);
        isVisible = true;
    }

    public void UpdateHealth(float current, float max)
    {
        targetFill = Mathf.Clamp01(current / max);
        if (healthValueText != null) healthValueText.text = $"{Mathf.Max(0, Mathf.CeilToInt(current))} / {Mathf.CeilToInt(max)}";

        if (current <= 0f)
        {
            HideBoss(false);
        }
    }

    public void HideBoss(bool instant = false)
    {
        isVisible = false;
        if (instant)
        {
            if (canvasGroup != null) canvasGroup.alpha = 0f;
            gameObject.SetActive(false);
        }
    }
}